Do you have the need to track your time across different projects?
Maybe you're billing for consulting hours or just trying to keep
track of how much time you spend on email vs. coding vs. meetings. There are a zillion timer apps out there that all
suck. I finally found one I like: Slimtimer.

Slimtimer is web based. That sounds terrible, but the little tracker app
has just enough Javascript and AJAX love to work well. In particular,
it's smart to not break when you close the browser without stopping
your current task. And since all the data lives on someone's web
server you can access it anywhere, get a lot of fancy reports, access
it via an API, etc.

My only complaint is it's a bit geeky. Everything is tracked down to
the seconds. And getting a simple time sheet involves the words
"Pivot" and "Rows" and "Columns". But it's still all very usable, and
in general the application is very well executed. Recommended.